JP4166037B2 - Absorption chiller / heater - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an absorption chiller / heater.
[0002]
[Prior art]
As shown in FIG. 3, the high-temperature regenerator 1, the low-temperature regenerator 3, the condenser 4, the evaporator 6, the absorber 7, the low-temperature heat exchanger 9, the high-temperature heat exchanger 10, and the absorption liquid pump provided with the gas burner 2. 17, the refrigerant pump 22 and the like are connected by the absorption liquid pipe and the refrigerant pipe, and the refrigerant vapor evaporated and separated from the absorption liquid heated by the high temperature regenerator 1 and the low temperature regenerator 3 is sent to the condenser 4 to pass through the inside of the cooling water pipe 24. Cooled with flowing cooling water and condensed, the condensed refrigerant liquid is sent to the evaporator 6 to evaporate, and cold water cooled by the evaporation heat of the refrigerant is circulated and supplied to the cooling load via the cold / hot water pipe 23. Cooling operation such as cooling, the refrigerant vapor evaporated and separated from the absorption liquid heated in the high-temperature regenerator 1, and the absorption liquid obtained by evaporating and separating the refrigerant are directly sent to the low-temperature cylinder 8 and heated mainly by the heat of condensation of the refrigerant. Hot water is circulated and supplied to the heating load via the cold / hot water pipe 23. And heating operation such as heating, is configured absorption chiller is well-known so as to select implementation.
[0003]
In the absorption chiller / heater configured as described above, the refrigerant tank 4A that stores the refrigerant liquid that has dissipated heat and condensed in the cooling water flowing inside the cooling water pipe 24 is provided inside the condenser 4, and is stored therein. The amount of refrigerant liquid is determined by the magnitude of the load. That is, when the cooling load is large, the concentration difference of the absorbing liquid becomes large (in other words, the amount of refrigerant in the refrigerant pool increases), and when the cooling load is small, the concentration difference of the absorbing liquid becomes small (in other words, the refrigerant pool Refrigerant amount decreases). Therefore, when the cooling water temperature is low and the low concentration / low load operation is performed, the refrigerant liquid is insufficient in the evaporator 6 and the refrigerant pump 22 may be damaged due to cavitation.
[0004]
Further, when the cooling operation such as cooling is stopped, the on-off valve V4 is manually opened so that the absorption liquid heated and concentrated does not crystallize even if the temperature is lowered, and the refrigerant accumulated in the evaporator 6 In addition to returning the liquid to the absorber 7 and diluting the absorbing liquid, the refrigerant liquid in the refrigerant tank 4 </ b> A is also returned to the absorber 7.
[0005]
[Problems to be solved by the invention]
However, since the conventional absorption chiller / heater has a structure in which all of the refrigerant stored in the refrigerant tank of the condenser is returned to the absorber, the absorption liquid is more than necessary when the refrigerant is returned from the refrigerant tank to the absorber. However, when the cooling operation is restarted, it takes a long time to secure a necessary amount of refrigerant, and there is a problem that the cooling time to the set temperature may be greatly extended.
[0006]
Therefore, the temperature of the cooling water is low and the evaporator does not run out of refrigerant even during low-concentration / low-load operation, so that the refrigerant pump does not cause cavitation, and the absorption liquid does not crystallize when the cooling operation is stopped. In addition, when resuming the cooling operation, it is necessary to allow an appropriate dilution so that a necessary amount of refrigerant can be secured in a short time and can be quickly cooled to the set temperature. Met.
[0007]
[Means for Solving the Problems]
In order to solve the above problems, the present invention
Evaporator-absorber-regenerator-condenser connected to circulate and the absorption liquid refrigerant and a cooling operation for cooling the brine by evaporation heat of the cold medium, mainly by heat of condensation of the above-described refrigerant In the absorption chiller / heater that can selectively carry out the heating operation for heating the brine,
A refrigerant liquid storage unit for storing the refrigerant liquid condensed by dissipating the refrigerant to the cooling water in the condenser;
A refrigerant liquid outflow passage for causing the refrigerant liquid overflowing from the refrigerant liquid storage section to flow out;
In order to allow the overflowing refrigerant liquid to flow into the evaporator by connecting the refrigerant liquid outflow path to the evaporator with a first refrigerant pipe provided with a U-shaped hanging portion. A first refrigerant liquid inflow path,
The bottom part of the refrigerant liquid storage part is stored in the refrigerant liquid storage part by connecting the bottom part of the refrigerant liquid storage part to the first refrigerant pipe by a second refrigerant pipe through which an on-off valve or a flow control valve is interposed. A second refrigerant liquid inflow passage for allowing the refrigerant liquid to flow into the evaporator;
During the cooling operation, the on-off valve is closed / opened based on the high / low temperature of the cooling water, or the valve opening of the flow control valve is set to the temperature of the cooling water. Valve control means for controlling in inverse proportion;
A first configuration of the absorption chiller having a,
[0008]
In the absorption chiller / heater of the first configuration described above
In place of the second refrigerant inflow path,
The bottom of the refrigerant liquid reservoir is connected to the evaporator or the absorber by a second refrigerant pipe with an on-off valve or a flow rate control valve interposed therein, whereby the refrigerant liquid reservoir is stored in the refrigerant liquid reservoir. An absorption chiller / heater having a second configuration provided with a third refrigerant liquid inflow passage for allowing the refrigerant to flow into the evaporator or the absorber ;
[0009]
In the above-mentioned first absorption chiller / heater, or the absorption chiller / heater of the second configuration,
When the cooling operation is stopped, if the outside air temperature is equal to or lower than the predetermined temperature, the absorption chiller / heater of the third configuration provided with the outside air temperature valve control means for controlling the on-off valve to open. And provide.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to FIGS. 1 and 2. In order to facilitate understanding, in these drawings, parts having the same functions as those described with reference to FIG.
[0011]
In the embodiment of the present invention shown in FIG. 1, an absorption chiller / heater using water as a refrigerant and a lithium bromide (LiBr) aqueous solution as an absorption liquid is used.
Then, the refrigerant tank 4A, that is, the refrigerant liquid outflow path 4b for allowing the refrigerant liquid overflowing from the refrigerant liquid storage section to flow out is connected to the evaporator 6 by the refrigerant pipe 20 provided with the U-shaped hanging portion 20a. As a result, the refrigerant liquid is supplied to the evaporator 6 through the refrigerant liquid inflow path in which the overflowing refrigerant liquid flows into the evaporator 6.
Further, the refrigerant tank 4A, that is, the bottom of the refrigerant liquid storage part is connected to the refrigerant pipe 20 by the refrigerant pipe 20A having the open / close valve V3, whereby the refrigerant liquid 4a stored in the refrigerant tank 4A is supplied to the evaporator 6. The refrigerant liquid is also supplied to the evaporator 6 through the refrigerant liquid inflow path that is allowed to flow, and the amount of the refrigerant liquid supplied from the refrigerant tank 4A to the evaporator 6 can be controlled by opening and closing the on-off valve V3. It has become.
[0012]
Reference numeral C is a control device of the present invention configured with a microcomputer or the like, and the on-off valve V3 is appropriately opened and closed as will be described later by a control program stored in a storage unit (not shown) of the controller C. The
[0013]
In the absorption chiller / heater having the above-described configuration, the on-off valves V1 to V4 are closed and the cooling water is supplied to the cooling water pipe 24, while the gas burner 2 burns city gas and the like, and the high temperature regenerator 1 heats the rare absorbent. When boiling, a refrigerant vapor evaporated and separated from the rare absorption liquid and an intermediate absorption liquid in which the concentration of the absorption liquid is increased by separating the refrigerant vapor are obtained.
[0014]
The high-temperature refrigerant vapor generated in the high-temperature regenerator 1 passes through the upstream portion of the refrigerant pipe 19 and enters the low-temperature regenerator 3, and is generated in the high-temperature regenerator 1 and passes through the high-temperature heat exchanger 10 through the absorption liquid pipe 15. Then, the intermediate absorption liquid that has entered the low-temperature regenerator 3 is heated and condensed, and enters the condenser 4 through the downstream portion of the refrigerant pipe 19 in which the refrigerant drain heat recovery unit 11 is interposed.
[0015]
Further, the refrigerant heated by the low temperature regenerator 3 and evaporated and separated from the intermediate absorption liquid enters the condenser 4, exchanges heat with the cooling water flowing in the cooling water pipe 24 to be condensed and liquefied, and is condensed and supplied from the refrigerant pipe 19. The refrigerant 6 enters the evaporator 6 through the refrigerant pipe 20 together.
[0016]
The refrigerant liquid accumulated in the refrigerant pool of the evaporator 6 is sprayed by the refrigerant pump 22 interposed in the refrigerant pipe 21 on the heat transfer pipe 23 </ b> A connected to the cold / hot water pipe 23 and supplied through the cold / hot water pipe 23. Heat is exchanged with the water to be evaporated, and the water flowing inside the heat transfer tube 23A is cooled.
[0017]
The refrigerant evaporated by the evaporator 6 enters the absorber 7 and is heated by the low-temperature regenerator 3 to evaporate and separate the refrigerant. The absorption liquid whose concentration of the absorption liquid is further increased is transferred from the absorption liquid pipe 16 to the low-temperature heat exchanger 9. Is supplied to the absorber 8 via, and sprayed from above in the absorber 7.
[0018]
Then, the absorption liquid whose concentration has been reduced by absorbing the refrigerant by the absorber 7, that is, the rare absorption liquid, is returned to the high-temperature regenerator 1 by the operation of the absorption liquid pump 17.
[0019]
When the absorption chiller / hot water machine is operated as described above, the chilled water cooled by the heat of vaporization of the refrigerant in the heat transfer pipe 23A piped inside the evaporator 6 is not shown through the cold / hot water pipe 23. Since it can be circulated and supplied, it can be cooled and cooled.
[0020]
In the absorption chiller / heater configured as described above, the on-off valves V1 and V2 are opened, and the city gas and the like are burned by the gas burner 2 without flowing the cooling water through the cooling water pipe 24. When the liquid is heated to boiling, the refrigerant vapor evaporated and separated from the rare absorption liquid and the absorption liquid with the concentration of the absorption liquid increased by separating the refrigerant vapor are obtained. Any but three will enter the absorber 7.
[0021]
Then, the refrigerant vapor entering the absorber 7 enters the adjacent evaporator 6, dissipates heat to the water flowing in the cold / hot water pipe 23 </ b> A, condenses, and heats the water flowing in the cold / hot water pipe 23. The refrigerant liquid condensed in the evaporator 6 overflows and returns to the absorber 7, is mixed (absorbed) with the absorption liquid that has entered from the absorption liquid pipe 15 </ b> A, and is returned to the high-temperature regenerator 1 by the absorption liquid pump 17.
[0022]
When the absorption chiller / heater is operated as described above, the hot water heated mainly by the heat of condensation of the refrigerant in the heat transfer pipe 23A piped inside the evaporator 6 is not shown via the cold / hot water pipe 23. Since it can be circulated and supplied to the air conditioning load, heating operation such as heating can be performed.
[0023]
In the absorption chiller / heater of the present invention, when the chilled water cooled by the heat transfer pipe 23A in the evaporator 6 is circulated and supplied from the cold / hot water pipe 23 to the load to perform a cooling operation such as cooling, the controller C For example, as shown in FIG. 2A, the on-off valve V3 is closed when the cooling water inlet temperature detected by the temperature sensor S1 installed on the inlet side of the absorber 7 of the cooling water pipe 24 becomes a predetermined temperature, for example, 25 ° C. or more. The temperature sensor S1 is configured to open when the coolant inlet temperature detected by the temperature sensor S1 becomes another predetermined temperature, for example, 20 ° C. or less (the set temperature is variable on a microcomputer or the like).
That is, the on-off valve V3 is closed when the temperature is higher than the predetermined temperature of the cooling water, and the on-off valve V3 is opened when the temperature is lower than the predetermined temperature of the cooling water. The on-off valve is controlled to be closed / open based on high / low ”.
[0024]
Therefore, when the temperature of the cooling water supplied from the cooling water pipe 24 to the absorber 7 is low and the absorption of the refrigerant by the absorption liquid in the absorber 7 is likely to proceed, and therefore the amount of the refrigerant in the evaporator 6 tends to be insufficient. Since the on-off valve V3 interposed in the refrigerant pipe 20A is opened and the refrigerant liquid in the refrigerant tank of the condenser 4 is supplied to the evaporator 6 through the refrigerant pipes 20A and 20, the low-concentration and low-load operation is performed. However, there is no concern that the refrigerant is insufficient in the evaporator 6 and the refrigerant pump 22 causes cavitation.
[0025]
Note that the opening / closing valve V3 interposed in the refrigerant pipe 20A is changed to a flow rate control valve V3 whose opening degree can be freely controlled, and the opening degree is controlled by the controller C, for example, as shown in FIG. Even if the detected cooling water inlet temperature is controlled as a variable in inverse proportion (the set temperature is variable on a microcomputer or the like), the same effect as described above can be obtained.
[0026]
In addition, when the controller C stops the combustion of the gas burner 2 and ends the cooling operation such as cooling, the controller C opens the on-off valve V4 after stopping the combustion of the gas burner 2, and opens the refrigerant pump 22 for a predetermined time, for example, 10 minutes. The refrigerant liquid accumulated in the refrigerant reservoir of the evaporator 6 is transferred to the absorber 7 through the refrigerant pipe 21A, and the absorption liquid diluted with the refrigerant supplied from the evaporator 6 is converted into the high temperature regenerator 1, It is configured so as to circulate and supply to the regenerator 3 and so on to dilute the entire absorbent.
[0027]
Furthermore, when the outside air temperature detected by the temperature sensor S2 is a predetermined temperature, for example, 5 ° C. or less, the controller C opens the on-off valve V3 interposed in the refrigerant pipe 20A (the opening time is based on the outside air temperature). The refrigerant liquid accumulated in the refrigerant tank 4A in the condenser 4 is supplied to the absorber 7 via the evaporator 6 so that the absorption liquid can be further diluted. It is. Therefore, the absorption liquid does not crystallize even in a cold region, and unnecessary dilution does not occur.
[0028]
That is, according to the absorption chiller / heater of the present invention, it is possible to perform a dilution operation that does not crystallize the absorbing solution even in a cold region, and an unnecessary dilution operation is not performed. A necessary amount of the refrigerant can be evaporated and separated in a short time, and a cooling operation such as cooling can be quickly started.
[0029]
When the controller C circulates and supplies hot water heated by the heat transfer pipe 23A in the evaporator 6 to the load from the cold / hot water pipe 23 to perform heating operation such as heating, the on-off valve V3 interposed in the refrigerant pipe 20A. Therefore, the refrigerant liquid stored in the refrigerant tank 4A in the condenser 4 during the cooling operation such as cooling is returned to the absorber 7 via the evaporator 6 and is absorbed. Mixed (absorbed).
[0030]
Therefore, the concentration of the absorbing liquid circulating in the machine is reduced to the whole, and the temperature level of the cycle is lowered, so that the durability of the absorption chiller / hot water machine is improved.
[0031]
In addition, since this invention is not limited to the said embodiment, various deformation | transformation implementation is possible in the range which does not deviate from the meaning as described in a claim.
[0032]
For example, the refrigerant pipe 20A in which the on-off valve V3 is interposed can be provided so as to reach the evaporator 6 or the absorber 7 directly from the refrigerant tank 4A.
[0033]
Further, during the cooling operation in which cold water is circulated and supplied from the cold / hot water pipe 23, when the combustion of the gas burner 2 has stopped for a predetermined time, for example, more than 5 minutes, the temperature sensor S1 has a temperature lower than the predetermined 20 ° C. It is also possible to configure the controller C so as not to output a valve opening signal for the on-off valve V3 even if it is detected. By configuring the controller C in this way, unnecessary opening operation of the on-off valve V3 can be avoided.
[0034]
The fluid to be circulated to the cold / hot water pipe 23 in order to supply to such an air conditioning load by such as cooling in the evaporator 6, i.e., the brine that has been described in the above range of solutions and claims, water, etc. May be supplied without changing the phase as in the above embodiment, or may be supplied with changing the phase of chlorofluorocarbon or the like so as to enable heat transfer using latent heat.
[0035]
【The invention's effect】
As described above, in the absorption chiller / heater of the present invention, the refrigerant liquid evaporated by the evaporator is not insufficient even during low concentration / low load operation where the temperature of the cooling water is sufficiently low, and the refrigerant pump causes cavitation. There is no concern.
[0036]
In addition, in an absorption chiller / heater in which the control means has a function of opening the flow valve during the heating operation, the concentration of the absorbing liquid circulating in the apparatus decreases during the heating operation such as heating, and the temperature level of the cycle As a result, the durability of the absorption chiller / heater is improved.
[0037]
Further, in the absorption chiller / heater in which the control means has a function of opening the flow rate control valve based on the outside air temperature when the cooling operation is stopped when the outside air temperature is lower than the predetermined temperature, the absorption liquid The absorption liquid is diluted so that it does not crystallize, but unnecessary dilution is not performed, so the refrigerant required for cooling operation such as cooling can be evaporated and separated in a short time, and cooling etc. can be performed quickly. Can start.
[Brief description of the drawings]
FIG. 1 is an explanatory diagram showing an embodiment of the present invention.
2A and 2B are explanatory views showing a control example of the absorption chiller / heater shown in FIG. 1, in which FIG. 2A is a control example in which opening and closing control is performed using a valve interposed in the refrigerant pipe 20A, and FIG. This is a control example in which the opening degree is controlled by using a valve interposed in 20A as a flow control.
FIG. 3 is an explanatory diagram showing a conventional technique.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 High temperature regenerator 2 Gas burner 3 Low temperature regenerator 4 Condenser 4A Refrigerant tank 5 High temperature cylinder 6 Evaporator 7 Absorber 8 Low temperature cylinder 9 Low temperature heat exchanger 10 High temperature heat exchanger 12-16 Absorption liquid pipe 17 Absorption liquid pump 19 21 Refrigerant pipe 22 Refrigerant pump 23 Cold / hot water pipe 23A Heat transfer pipe 24 Cooling water pipe C Controllers S1 and S2 Temperature sensors V1 to V4 On-off valve

Claims (3)

Evaporator-absorber-regenerator-condenser connected to a by circulating the absorbing solution and refrigerant, and the cooling operation for cooling the brine by evaporation heat of the refrigerant, a brine by condensation heat mainly the refrigerant In an absorption chiller / heater that can be selectively operated with heating operation ,
A refrigerant liquid storage section for storing the refrigerant liquid condensed by dissipating the refrigerant to the cooling water in the condenser;
A refrigerant liquid outflow passage for flowing out the refrigerant liquid overflowing from the refrigerant liquid storage section;
The refrigerant liquid outflow path is connected to the evaporator by a first refrigerant pipe provided with a U-shaped drooping portion, thereby allowing the overflowing refrigerant liquid to flow into the evaporator. A refrigerant liquid inflow path;
The refrigerant liquid stored in the refrigerant liquid storage section by connecting the bottom of the refrigerant liquid storage section to the first refrigerant pipe through a second refrigerant pipe with an on-off valve or a flow control valve interposed therebetween. A second refrigerant liquid inflow passage for allowing the refrigerant to flow into the evaporator;
During the cooling operation, the on-off valve is closed / opened based on the high / low temperature of the cooling water, or the valve opening degree of the flow control valve is controlled in inverse proportion to the temperature of the cooling water. Valve control means to
Absorption chiller / heater characterized by the provision of Instead of the second refrigerant inflow path,
The refrigerant stored in the refrigerant liquid storage unit by connecting the bottom of the refrigerant liquid storage unit to the evaporator or the absorber by a second refrigerant pipe with an on-off valve or a flow rate control valve interposed therebetween. The absorption chiller / heater according to claim 1, further comprising a third refrigerant liquid inflow passage through which the refrigerant flows into the evaporator or the absorber .   The outside air temperature valve control means is provided for controlling the open / close valve to open when the outside air temperature is equal to or lower than a predetermined temperature when the cooling operation is stopped. 2. Absorption cold / hot water machine of 2 description.

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